PDF 函数

简介

The PDF functions in PHP can create PDF files using the PDFlib
library which was initially created by Thomas Merz and is now
maintained by » PDFlib GmbH.

The documentation in this section is only meant to be an overview
of the available functions in the PDFlib library and should not be
considered an exhaustive reference. For the full and detailed
explanation of each function, consult the PDFlib Reference Manual
which is included in all PDFlib packages distributed by PDFlib GmbH.
It provides a very good overview of what PDFlib is capable of doing
and contains the most up-to-date documentation of all functions.

For a jump start we urge you to take a look at the programming samples
which are contained in all PDFlib distribution packages. These samples
demonstrate basic text, vector, and graphics output as well as
higher-level functions, such as the PDF import facility (PDI).

All of the functions in PDFlib and the PHP module have identical
function names and parameters. Unless configured otherwise, all
lengths and coordinates are measured in PostScript points. There are
generally 72 PostScript points to an inch, but this depends on the
output resolution. Please see the PDFlib Reference Manual
included in the PDFlib distribution for a more thorough explanation
of the coordinate system used.

With version 6, PDFlib offers an object-oriented API for PHP 5 in
addition to the function-oriented API for PHP 4. The main difference is
the following:

In PHP 4, first a PDF resource has to be retrieved with a function call
like

$p = PDF_new().

This PDF resource is used as the first parameter in all further function
calls, such as in

PDF_begin_document($p, "", "").

In PHP 5 however, a PDFlib object is created with

$p = new PDFlib().

This object offers all PDFlib API functions as methods, e.g. as with

$p->begin_document("", "").

In addition, exceptions have been introduced in PHP 5 which are
supported by PDFlib 6 and later as well.

Note:
If you're interested in alternative free PDF generators that do not
utilize external PDF libraries, see
this related FAQ.

需求

PDFlib Lite is available as open source. However, the
PDFlib Lite license allows free use only under certain conditions.
PDFlib Lite supports a subset of PDFlib's functionality; please see the
PDFlib web site for details. The full version of PDFlib is available for
download at » http://www.pdflib.com/products/pdflib-family/, but requires that
you purchase a license for commercial use.

Issues with older versions of PDFlib

Any version of PHP 4 after March 9, 2000 does not support versions
of PDFlib older than 3.0.

资源类型

Remarks about Deprecated PDFlib Functions

Starting with PHP 4.0.5, the PHP extension for PDFlib is
officially supported by PDFlib GmbH. This means that all the
functions described in the PDFlib Reference Manual are
supported by PHP 4 with exactly the same meaning and the same
parameters. However, with PDFlib Version 5.0.4 or higher all parameters
have to be specified. For compatibility reasons, this binding for PDFlib
still supports most of the deprecated functions, but they
should be replaced by their new versions. PDFlib GmbH will not
support any problems arising from the use of these deprecated
functions. The documentation in this section indicates old functions as
"Deprecated" and gives the replacement function to be used instead.

范例

Most of the functions are fairly easy to use. The most difficult part
is probably creating your first PDF document. The following
example should help to get you started. It is developed for PHP 4 and
creates the file hello.pdf with one page.
It defines some document info field contents, loads the Helvetica-Bold
font and outputs the text "Hello world! (says PHP)".

The following example comes with the PDFlib distribution for PHP 5.
It uses the new exception handling and object encapsulation features
available in PHP 5. It creates the file hello.pdf
with one page. It defines some document info field contents, loads the
Helvetica-Bold font and outputs the text "Hello world! (says PHP)".